1. Field of the Invention
This invention relates broadly to surgical instruments. More particularly, this invention relates to ports for surgical instruments. In addition, the invention relates to an improved technique for performing surgery through a surgical port device.
2. State of the Art
Endoscopic surgical procedures are facilitated by the use of surgical ports (commonly referred to as “trocars”) that provide access into the human body. Various endoscopic surgical instruments (e.g., imaging probes, cutting blades, clamps/suturing devices, etc.) are inserted into a body cavity (such as the chest cavity) via such ports and are manipulated in the cavity. Surgical ports are also used in laparoscopic surgical procedures to provide access into the abdominal cavity for insertion and manipulation of various laparoscopic surgical instruments therein. Typically, such surgical ports employ a cannula as the passageway for the various endoscopic/laparoscopic instruments. Often, internal pressures in the body cavity are elevated by insufflation via an external pressure source operably coupled to the body cavity through an inlet in the surgical port. In such configurations, the surgical ports often employ gaskets disposed upstream from the inlet that maintain the elevated internal pressures in the body cavity while inserting/removing instruments through the cannula of the port.
U.S. Pat. No. 5,817,062 to Flom et al. and U.S. Pat. No. 5,830,191 to Hildwein et al. disclose two exemplary surgical ports. Each employs a flexible member at the distal end of a tubular structure in addition to a flange fixed in place at the proximal end of the tubular structure. However, the surgical ports of U.S. Pat. Nos. 5,817,062 and 6,830,191 suffer from many drawbacks, and are not widely used commercially.
A first drawback to these ports in the fixed distance between the flexible member and the flange of the respective surgical ports. Thus, these surgical ports employ a clamping action of body tissue between the flexible member and the flange for a limited range of body wall thicknesses, and are effective in securely affixing the surgical port to the entrance site over this limited range of body wall thickness. In the event that the body wall of the entrance site lies outside this limited range (e.g., the body wall is too small or too big), the effectiveness of such surgical ports is adversely impacted.
A second drawback arises when body secretions and blood runs down the inside surface of the body cavity and flows over the flexible member. This fluid can interfere with proper operation of the medical instrument inserted through the surgical port. For example, it is commonplace for the optics of an endoscope/laparoscope to be retracted such that the optics are positioned essentially flush to the inside surface of the body wall. This configuration maximizes the field of view of the optics within the body cavity. However, in this configuration, any body fluid that flows down the inside surface of the body cavity in the vicinity of the surgical port will smudge the optics. The operator is then required to remove the endoscope/laparoscope from the surgical port, clean the fluid from the optics, and reinsert the endoscope/laparoscope through the surgical port. This extended procedure causes safety concerns and physician frustration, and extends the procedure time.
The surgical port of U.S. Pat. No. 5,830,191 also suffers from the drawback that its tubular structure is flexible and thus fails to provide structural support for non-rigid instruments that pass through it. When the orientation of the port is manipulated such that its angle of entry diverges substantially from the angle of the entrance site made through the body wall, the body wall exerts forces on the flexible tubular structure such that its binds on the surgical instrument passing therethrough. This binding action interferes with normal operation of the surgical instrument (i.e., the surgical instrument is not able to freely move through the port).
Thus, there remains a need in the art for improved surgical port devices that overcome the limitations provided by these prior art port devices.